1. Field of the Invention
The invention relates to a valve for an inflatable device, more particularly to an air valve that is capable of preventing air leakage when a connection head of an inflation device is removed therefrom.
2. Description of the Related Art
FIG. 1 shows a conventional valve 91 mounted on an inflatable object 92, such as an inflatable cushion, to inflate and deflate the inflatable object 92. The valve 91 includes a hollow valve seat 93 coupled to the inflatable object 92, and a valve cap 95 that is connected to the valve seat 93 via a connecting strip 94 and that has an internal thread portion 951 for engaging an external thread portion 931 of the valve seat 93. After inflation of the inflatable object 92, the valve cap 95 is sleeved on the external thread portion 931 to prevent leakage of air from the inflatable object 92 via the valve seat 93.
During the actual process of inflation, a connection head (not shown) of an inflation device, such as an air compressor (not shown), is connected to the valve seat 93. When the inflatable object 92 has been inflated to a desired extent, the connection head has to be detached from the valve seat 93 to allow closing of the valve seat 93 using the valve cap 95. At that interval of time, some of the air will escape from the inflatable object 92. To minimize the undesirable escape of air from the inflatable object 92, the user has to close the valve cap 95 very quickly, which is quite annoying.